A variety of expandable intraluminal medical devices have been developed over recent years. Stents, for example, are routinely used in several body lumens as a means for providing support to ailing vessels, such as coronary and non-coronary vessels. Stent-graft devices are frequently used to provide support from within a body vessel and/or to exclude a portion of a vessel wall from the lumen of the vessel. Prosthetic valves, including heart and venous valve devices, that include expandable support frames have also been the focus of considerable development efforts over the last several years.
Irrespective of the ultimate function of the device, expandable intraluminal medical devices are typically delivered to a point of treatment using a delivery system designed for percutaneous techniques. In a conventional procedure, a caregiver navigates the delivery system through one or more body vessels until the expandable intraluminal medical device, which is typically contained within a distal tip or portion of the delivery system, is positioned at or near the desired point of treatment. Next, the caregiver deploys the expandable intraluminal medical device from the delivery system, either by removing a constraining force for self-expandable devices or by providing an expansive force for balloon-expandable devices. Once deployment is complete, the delivery system is removed from the body vessel, leaving the expandable intraluminal medical device at the point of treatment.
During delivery, expandable intraluminal medical devices are maintained in a reduced-diameter configuration within the delivery system to ensure navigability of the delivery system through the body vessel. It is necessary, therefore, to compress the intraluminal medical device and place it within the delivery system at some time prior to use in the treatment procedure. For some devices, including some cardiac stents, this loading procedure can be conducted as part of the manufacturing process, i.e., prior to shipment to the treatment facility. For other devices, however, various concerns caution against loading the device at any time not immediately prior to delivery. For example, some tissue-based devices, such as prosthetic heart and venous valves, must be maintained in an appropriate fluid during all storage periods prior to use in a treatment procedure to ensure the integrity of the tissue component of the device. Furthermore, the effects of reduced-diameter storage of such tissue-based devices, particularly long-term storage, are not well-characterized and, as a result, are desirably avoided at this time.
A loading procedure that is conducted immediately prior to treatment is subject to several concerns not considered critical for such procedures conducted outside of the treatment theater. For example, the loading procedure must not require bulky equipment that is difficult to use and/or inappropriate for the treatment theater. The procedure must be efficient and simple, and any materials or devices used in such a procedure should be easy to handle and operate. A need exists, therefore, for a simple apparatus that facilitates loading of an expandable intraluminal medical device into a delivery device. A need for improved methods of loading expandable intraluminal medical devices into delivery devices also exists.